Fluid dispensing containers are utilized for storing fluid and for dispensing fluid to a receiving vessel. For example, fluid dispensing containers have been used for dispensing fuel to fuel tanks associated with small, internal-combustion engines, such as those used in lawnmowers, weed trimmers and other motorized devices.
Some fluid dispensing containers are specially designed to automatically cut off the flow of fluid from the container when the fluid in the receiving vessel reaches a predetermined level (i.e., an "auto-stop dispenser"). To accomplish this, the container is typically completely sealed except for a discharge port in a pour spout. When fluid is being dispensed from the container into a receiving vessel, the discharge port is positioned within the receiving vessel, and air entering the container must travel up through the discharge port. When the level of the fluid in the receiving vessel is high enough such that it covers the discharge port, the flow from the container will automatically stop since no more air can enter the container.
Some pour spout designs further include an air vent passageway within the pour spout for allowing air to enter the container without significantly affecting the flow of fluid through the discharge port. That is, air is allowed to enter the container in a smooth, controlled manner, thereby avoiding intermittent surging of the fluid. When utilizing an air vent in conjunction with an auto-stop design, fluid will continue to flow from the container until the fluid within the receiving vessel covers the inlet to the air vent.
In order to prevent fluid flow from the container when the pour spout is not properly positioned within the receiving vessel (e.g., before or after the pour spout is inserted into the receiving vessel), some pour spouts are provided with a biased closure device which covers and seals the discharge port when the pour spout is not completely inserted into a receiving vessel. For example, in one design, the pour spout can be pushed into the receiving vessel to force the closure member to its open position, thereby uncovering the discharge port.
To prevent fluid vapors (e.g., fuel vapors) from exiting the container during storage, many of the above-identified containers are designed to be completely sealed when not in use. Due to the volatile nature of the fluids which can be stored in such containers, the vapor pressure within the containers can rise significantly beyond atmospheric pressure, particularly when the container is stored for a long period of time and/or exposed to elevated temperatures. Because of the high pressure within the container, when a pour spout having a biased closure device is inserted into a receiving vessel and the closure device is opened, the fluid within the container has a tendency to spurt out at a rapid pace. This situation is undesirable in that it can result in splashing and spilling fluid and/or discharging more fluid than is desired, resulting in an overfilled receiving vessel.
In addition, since the above-described containers can be opened by merely axially moving the closure device, such containers can be susceptible to leaking, especially if the container tips over. For example, if the container is tipped onto its side, there is potential that the closure device may contact an object and be moved to its open position, thereby allowing fluid to exit the pour spout and spill onto surrounding objects.